title: Reproductive toxicity in adult male rats following intra-articular injection of cobalt-chromium nanoparticles.
abstract: BACKGROUND
  Recent studies have reported that metallic nanoparticles and ions from cobalt-chromium (CoCr) alloy prostheses had potential adverse effects. However, the biological effects of CoCr nanoparticles on male reproductive function remain unclear. The objective of this study is to investigate the reproductive toxicity in adult male rats following intra-articular injection of cobalt-chromium nanoparticles.
  
  
  METHODS
  CoCr nanoparticles were generated by a spark discharge method. Adult male rats received intra-articular injections of CoCr nanoparticles once a week at a low (20 μg/kg b.w.), medium (100 μg/kg b.w.) or high dose (500 μg/kg b.w.) for 10 consecutive weeks. The control group received intra-articular injections of physiological saline. After the final injection, all rats were held for a 7-day post-exposure period. The effects on male reproductive function were observed, including the coefficient of testicular to body weight, the epididymal sperm parameters, the concentration of metal ions in serum and testis, the activity of antioxidase and the content of lipid peroxide in the testis, and histopathological examination.
  
  
  RESULTS
  Compared with the control group, intra-articular injection of high dose CoCr nanoparticles could significantly reduce epididymal sperm motility, viability and concentration, increase abnormal sperm rate and levels of Co and Cr ions in serum and in the testis, and induce testicular damage and pathological changes via oxidative stress.
  
  
  CONCLUSIONS
  Intra-articular injection of high dose CoCr nanoparticles from MOM articulation may have potential reproductive toxicity in adult male rats.
authors.affiliation: Department of Orthopedics, The First Affiliated Hospital of Nanjing Medical University, 300 Guang Zhou Road, 210029, Nanjing, China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Wang
authors.forename: Zhefeng
authors.initials: Z
authors.lastname: Chen
authors.forename: Qiang
authors.initials: Q
authors.lastname: Zuo
authors.forename: Fanglong
authors.initials: F
authors.lastname: Song
authors.forename: Dongying
authors.initials: D
authors.lastname: Wu
authors.forename: Wendan
authors.initials: W
authors.lastname: Cheng
authors.forename: Weimin
authors.initials: W
authors.lastname: Fan
mesh_terms: D000818:Animals; D001707:Biopsy, Needle; D002857:Chromium / Q000633:toxicity*; D003035:Cobalt / Q000494:pharmacology / Q000633:toxicity*; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D007150:Immunohistochemistry; D007270:Injections, Intra-Articular; D008297:Male; D053768:Metal Nanoparticles / Q000633:toxicity*; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D012016:Reference Values; D012098:Reproduction / Q000187:drug effects; D012307:Risk Factors; D013081:Sperm Motility / Q000187:drug effects*; D013737:Testis / Q000187:drug effects* / Q000473:pathology
chemical_list: D002857:Chromium; D003035:Cobalt